Apparatus for producing sound



Dec. 4 1928.? I E. C. GUEDON APPARATUS FOR raonucme SOUND Filed my 18, 1927 2 Sheets-Sheet 1 Inventor: Emile C. Gue'don,

His Attorney.

Dec. 4, 1928. 1,694,319

v E. c. GUEDON I APPARATUS FOR PRODUCING SOUND Filed July 18, 1927 2 Sheets-Sheet 2 Inventor Emile C.Guedon,

His Att rneg Patented Dec. 4, 1928.

UNITED STATES EMILE C. GUEDON, OF SCHENECTAD'Y, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC I COMPANY, A CORPORATION OF NEW YORK. I

ABIARATUS FOR PRODUCING SOUND.

Application filed July 18, 1927. Serial No 206,408.

My invention relates to apparatus for producing sound and has for its principal ob ect the provision of an improved sound producing apparatus which is simpleand rugged n construction and may be readily operatedto convert electrical impulses into sound or vice versa.

Various apparatus have been provided in the past for converting electrical or mechanical impulses into sound. Many of these apparatus comprise parts which are moved either in accordance with electrical impulses dependent on sound or in accordance with the contour of a sound record. l/Vhen the operation of such apparatus involves the use of moving parts, difficulty is frequently encountered due to sound distortion produced by the tendency of these partsto v1b ra te at frequencies dependent on their individual free vibration periods. In accordance with my invention this difliculty ismininiized or altogether avoided by the pIOVlSlOIlOf means comprising an improved movable part which is light in weight and is so mounted that it rotates about an axis'near its center of mass.

My invention will be better understood from the following dcscri tion when considered in connection with t e accompanying drawings and its scope will be pointed out in the appended claims.

3 Referring to the. drawings, Fig. 1 llustrates certain details of a sound producing apparatus constructedin accordance with my invention; Figs. 2 to 6 illustrate various constructional features of this apparatus. Figs. 7 to 1 9 illustrate a modification in v the armature mounting of the apparatus Figs. 10 to 12 illustrate a further modification. m the armature mounting of the, a paratus; and Fig. 13 illustrate s a modification in the construction of the movable armature of the apparatus." v The sound producing apparatus illustrated by Fig. 1 comprises an electrlcal. device which is clamped to a support 1 by a pair of bolts 2 and is coupled to a conical diaphra gm 3 through a driving rod 1'. This device comprises armagnet 5 provided with b1- partite pole pieces 6 and 7 which are arrangedto support and partly enclose acoil 8 comprising leads 9 and 10. A movable armature 11 is pivoted within the coil 8 andis connected to the driving .rod 4 through a rod 12 and a resilient member 13 attached to one of thepole pieces 7 by means of a screw 14. As shownanore clearly by Fig. 2,

the armature 11 is made by folding a sheet,

of metal so that its opposed edges are slightly;

spaced from one another, and so that lugs.-

' ture a resilientpivotal connection which is located intermediate the ends of the armature near the rotational axis of the armature and tends to maintain opposite ends ofthe armature in predetermined positions between the pole pieces 6 and 7. It should be noted that the pole pieces are attached to the magnet 5 by means of screws 16 (see Fig.3) which preferably extend through slots in the ends of the magnet 5 and are arranged to permit adjustment of the gap between the pole pieces.

As indicatedmore clearly in Figs. 4 too-,- the armature 11 is made from a sheet 17 by punching out theen'ds of the lugs 15 and 16 and folding the sheet into the form shown by- Fig. 5. inserted in the tubular member '18 which is provided with slots 19 adapted to receive the lugs 15 and 17 and is attached to these lugs.

These lugs are In this form, the armature His.

In the operation of the apparatus,'electrical impulses from a suitable source are applied to the coil 8 through the leads 9-and '10; the opposite ends of the armature 11 are pulses dependent on the contour of the groove of .such a record and these impulses are-supplied to any'suitable amplifying or sound producing apparatus. v

The armature may be supported in various ways. I Fig, 7 shows a. resilient bar 20 which is inserted through slots in the side of an armature 21 and is pivoted'to the spool of the coilv 8 as previously described. It will of course be understood that the member 2Q the invention a driver rod 23 has one of its ends fitted into the slot of the armature and is threaded at its free end to permit its attaclnnenteither to a diaphragm or to a stylus holder.

The modification illustrated by Figs. 10 to 12 dilfer from those previously described in that an armature 24 is supported by means of a pair of resilient members 25 which are fixed either to the collar 22 or to the inner surface of the coil 8.

Fig. 13 shows an armature which is made by folding a T-shaped sheet so that the top of the T forms lugs 26 and 27 which are attached either to the inner surface of the spoolrorto the collar 22 as previously described.

It will be apparent that an armature made by folding a sheet of metal so that its oppo- 'site edges are slightly spaced from one another-possesses low inertia, is rigid, and is subject to low hysteresis and eddy current losses due .to the fact that it is both hollow and slotted. It has been found that when an armature is supported near its center of mass there is little, if any, tendency for it to vibrate at a frequency other than that corresponding to the sound to be transmitted.

-A.further advantage of this construction is that the armature and its pivotal sup ort lugs may be formed as an integral mem er, thus greatly simplifying the construction of the apparatus.

The embodimentsof the invention illustrated and described herein have been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, -that the invention is susceptible of being modified to meet the difierent conditions encountered in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope I of my, invention.

,WVhat I claim as new and desire to secure by Letters Patent of the United States, is.- 1. An integral armature member provided with opposed edges spaced from one another to form a slot and with outwardly extending mounting lugs.

2. The combination of means'for producinga magnetic field, a coil mounted insaid field, a sheet metal armature provided with opposed edges spaced from one another to form a slot and connected to said coil through a resilient connection for vary-'ing the path of the flux of said field through said coil, a

diaphragm, and means for coupling said armature to said diaphragm.

3. A sound producing apparatus comprising a hollow coil, and an integral armature member provided with opposed edges spaced apart to form a slot and with outwardly extending resilient lugs mechanically connected to the spool of said coil.

4. A sound producing apparatus comprisr said coil through a resilient connection, a diaphragm, a resilient member fixed to said coil at one end and to said diaphragm at the other end, means for connecting said armature to said resilient member at a point intermediate said ends, and means arranged to produce a magnetic field within said coil.

In witness whereof, I have hereunto set my hand this 16th day of July, 1927..

EMILE GGUEDON. 

